1. Technical Field
The present disclosure relates generally to backlight control for flat panel displays, such as liquid crystal displays, and more particularly, to a backlight control system and method for detecting and balancing high brightness contrast images.
2. Discussion of Related Art
Display devices often have a liquid crystal display for displaying images. Since liquid crystal displays (LCDs) do not emit light, LCDs display images by receiving light from a backlight section (or assembly) of the display device. The backlight section uses a light source (or lamp) to provide light to the LCD. The light source can include cold cathode fluorescent lamps (CCFLs), external electrode fluorescent lamps (EEFLs), hot-cathode fluorescent lamps (HCFLs), flat fluorescent lamps (FFLs), light-emitting diodes (LEDs), or combinations thereof. Dimming methods are implemented to control the amount of light the backlight section outputs to the LCD to enhance image quality and conserve power. For example, the display device can include an inverter that applies a dimming signal to the backlight section, thereby controlling the backlight section's brightness (light output). The inverter may use a pulse width modulation (PWM) method to repeatedly turn the backlight section's light source on and off according to a duty ratio of the dimming signal. A general dimming algorithm typically determines the duty ratio (also referred to as a dimming ratio), despite characteristics of the image to be displayed on the display device. The general dimming algorithm provides adequate brightness levels for general images, however, it often provides poor dimming quality for high brightness contrast images. For example, the dimming ratio determined by general dimming algorithms for high brightness contrast images is often too aggressive, resulting in poor dimming quality, or too conservative, resulting in poor power savings. Accordingly, although existing approaches for controlling brightness of a display device's backlight section have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects.